A lithography technology is a method capable of processing fine patterns on a target substrate, and in particular, a lithography technology having a nano/micro scale is an important core technology determining development, and success and failure, of semiconductor and display industries.
A basic limitation factor in fine patterning is a wavelength of light to be used for lithography, and in a case of a circuit having a line width of 0.8 μm or more, a mercury lamp (wavelength=365 nm) was used. However, in order to pattern a line width of 0.8 μm or less, new light source was needed, such that by using KrF (Kripton Fluoride) excimer laser (wavelength=248 nm), it is possible to process a line width of 0.13 μm, and for a process of a line width of 90 nm or less, ArF (Argon Fluoride) excimer laser (wavelength=193 nm) has been used.
In order to use a wavelength shorter than that of the ArF excimer laser, a fluorine excimer laser (wavelength=157) is needed to be used; however, there are various problems in that numerical aperture of a lens system is decreased, and the like. In a case of using an extreme ultraviolet, since significantly high-priced photo mask is required, there is commercial limit, and in a case of using an electron beam, a working speed is significantly slow and the related equipment has high price, thereby having a problem in commercialization.
To this end, Korean Patent Laid-Open Publication No. 2012-0132694 suggested an immersion lithography method using a liquid phase as a delivery media of light, and the like; however, in the method, overall replacement and development of the previously established lithography equipment are inevitable, such that there is a disadvantage in that an enormous cost and a research development are required to precede.
As described above, it may be judged that a method of implementing a fine line width by a new light source reached the limit, and thus, a novel technology capable of implementing a fine line width and high degree of integration, and patterning a structure having a diffraction limit or less in a photo mask with excellent precision at a low cost, while using the previously established lithography process and equipment, is required.